JPH10110072A - Sealant composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sealant compsn. which has a high hardness while retaining the characteristics of butyl rubber and which can give a double glazing by a primary sealing alone by compounding butyl rubber with a crystalline polyolefin. SOLUTION: This comsn. is prepd. by compounding 50-98wt.% butyl rubber with 2-50wt.% crystalline polyolefin. Pref. the compsn. further contains a filler in an amt. of up to 200 pts.wt. based on 100 pts.wt. the sum of the rubber and the polyolefin. Pref. the rubber has a relatively hgih-mol.-wt. and is an isobutylene homopolymer, an isobutylene-isoprene coplymer, or a partially vulcanized butyl rubber. Pref. the polyolefin is an ethylene or propylene homopolymer or an ethylene-propylene copolymer and has a crystallinity of 50% or higher. Further addition of additives, esp. zeolite as a drying agent, is pref. This compsn. is esp. suitable for sealing the edges of a double glazing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a sealant composition particularly suitable for edge sealing of a double glazing.

[0002]

2. Description of the Related Art Butyl rubber is used as a sealing agent for building materials because of its adhesiveness, high weather resistance and low moisture permeability. However, since it has low hardness and cold flow property, there is a problem in terms of long-term durability alone depending on the use application. There is also a problem that workability is poor due to high melt viscosity. There is also a method of mixing various fillers to improve the hardness, but if the hardness is increased only by adding the filler, the melt viscosity increases and the workability is significantly impaired, and in some cases, the tensile strength and tearing This is undesirable because the strength is reduced.

[0003]

When butyl rubber is used as an edge sealing material for double-glazing, a metal spacer such as aluminum is usually used because of the low hardness of the butyl rubber. Butyl rubber is disposed as a sealing material between the glass and the glass. Butyl rubber has the function of sealing the surface between the glass plate and the spacer and maintaining airtightness. However, the production process of the double glazing is complicated due to the necessity of using a metal spacer, and the development of a sealing agent that can further simplify the production process is desired.

[0004] Most of the present double glazings, like a double glazing 1 shown in FIG. 3, have at least two glass plates 1a and 1b opposed to each other via a metal spacer 2, and a hollow layer formed thereby. After the primary sealing material 3 made of butyl rubber is interposed between the glass plates 1a and 1b and the metal spacer 2 containing a desiccant, after being shielded from the outside air, the peripheral edges of the facing glass plates It is manufactured by a method in which a gap (recess) formed by the inner surface of the portion and the outer peripheral surface of the spacer is sealed with a secondary sealing material 5 made of a room-temperature-curable sealing agent represented by a polysulfide-based or silicone-based.

Heretofore, to simplify or automate the manufacturing process of a double-glazed glass, a method of bending an aluminum spacer has been used, and a method of applying a cold-curable sealing agent has also been automated. Improving the performance and eventually cost reduction have been studied and proposed. As shown in FIG. 4, a method has been proposed in which a resin in which a desiccant is kneaded is used as the spacer 4 instead of the aluminum spacer.

However, in the case of such a double-glazing using a cold-setting sealing agent, regardless of the type of spacer used, after the double-glazing is manufactured, a long curing time is required for curing the sealing agent. Unable to ship product until end. For that purpose, a curing space must be set up in the factory, and the products must be shipped after being stored for a certain period of time.
The delivery time was prolonged and it was not always possible to respond to customer requests. In order to respond to the demand that will increase in the future, more curing space is required than before. To avoid this, and to secure a sufficient supply of double glazing, It is considered necessary to shorten the time.

[0007] In view of the cost reduction of the double-glazed glass, there has been proposed a method of manufacturing the double-glazed glass without using a secondary sealing material by using a molded product made of a resin into which a desiccant is kneaded as a spacer. (Japanese Patent Publication No. 61-20501). However, this spacer resin has insufficient hardness as a spacer, and in fact, it has been difficult to maintain the shape of a double-layer glass using only the spacer made of the above resin.

Further, a double-layer glass using a material having a hardness of JIS A hardness (HsA) 95 obtained by kneading a desiccant into a hard resin extrudable, for example, a thermoplastic resin such as a vinyl chloride resin, as a spacer is disclosed. It is known (JP-A-7-17748). However, when a material having the hardness of HsA95 is used as a spacer or a sealing material for a double glazing, the stress applied to the sealing portion or the glass plate of the double glazing is large, and the peeling of the sealing portion and the double glazing There are disadvantages such as the occurrence of glass breakage.

At present, there is no known double glazing that does not use a secondary seal and only satisfies all of the properties such as life, shape retention and moldability with only a spacer required as a double glazing. An object of the present invention is to provide a sealant composition which is a material particularly useful as a sealant which does not substantially require such a secondary sealant in a double glazing.

[0010]

Means for Solving the Problems The present inventor has realized the high hardness of butyl rubber by a method as simple as possible while maintaining the properties of butyl rubber such as high temperature adhesiveness, weather resistance, and low moisture permeability. As a result of diligent studies on the method of performing the method, it has been found that the purpose can be achieved by adding a crystalline polyolefin. The present invention is the following sealant composition containing a butyl rubber and a crystalline polyolefin.

A butyl rubber and a crystalline polyolefin are contained, and the ratio of the butyl rubber to the total amount of both is 50 to 50%.
A sealant composition comprising 98% by weight and a crystalline polyolefin ratio of 2 to 50% by weight.

A butyl rubber, a crystalline polyolefin and an inorganic filler are contained, and the ratio of the butyl rubber to the total amount of the butyl rubber and the crystalline polyolefin is 50 to 98% by weight, and the ratio of the crystalline polyolefin is 2 to 50% by weight. And the total of butyl rubber and crystalline polyolefin is 10
A sealant composition wherein the ratio of the inorganic filler to 0 part by weight is 200 parts by weight or less.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The butyl rubber in the present invention refers to a homopolymer of isobutylene, a copolymer with another monomer, and a modified product thereof. The homopolymer includes a relatively high molecular weight homopolymer and a relatively low molecular weight homopolymer. The former has a molecular weight of usually 30,000 or more, and a typical one (such as a commercial product) is 50,000 to 150,000. The molecular weight of the latter is usually less than 30,000, and the typical one (commercially available) is 1
10,000 to 15,000. Here, the molecular weight means a viscosity average molecular weight (Staudinger molecular weight). When an isobutylene homopolymer is used as the butyl rubber in the present invention, a relatively high molecular weight homopolymer is used. A homopolymer having a relatively low molecular weight can be used in combination with another butyl rubber, and is usually used as an additive for the purpose of tackifying or plasticizing (reducing the viscosity). In addition, the polyisobutylene in an Example means these isobutylene homopolymers.

The copolymer is a polymer obtained by copolymerizing isobutylene and one or more copolymerizable monomers in a relatively small amount. Examples of the copolymerizable monomers include isoprene, 1-butene, and divinylbenzene. , P-methylstyrene and the like. As the copolymer, a copolymer obtained by copolymerizing with isoprene (usually called butyl rubber) is particularly preferred. Examples of the modified product include partially vulcanized butyl rubber obtained by partially vulcanizing halogenated butyl rubber such as chlorinated or brominated butyl rubber or butyl rubber. Particularly preferred butyl rubber in the present invention,
Isobutylene homopolymer having a relatively high molecular weight, a copolymer of isobutylene and isoprene, usually called butyl rubber, and partially vulcanized butyl rubber.

In the present invention, the crystalline polyolefin is
It refers to homopolymers of olefins such as ethylene and propylene, copolymers with other monomers, and modified products thereof, which have crystallinity. The structure of the polymer is preferably a syndiotactic structure or an isotactic structure, but may include other structures. As the olefin, ethylene and propylene are particularly preferable.

Examples of the copolymer include a copolymer of two or more olefins and a copolymer of olefin with another monomer, and a copolymer of ethylene or propylene with another monomer which does not inhibit crystallinity. Polymers are suitable. As the copolymer, a block copolymer is more suitable than an alternating copolymer or a random copolymer. Modified products include crystalline polyolefins into which functional groups such as acid anhydride groups, carboxyl groups, and epoxy groups have been introduced.

Particularly preferred crystalline polyolefins in the present invention are substantially homopolymers of polyethylene and polypropylene. For example, low density polyethylene, medium density polyethylene, high density polyethylene and the like can be used as polyethylene. The crystallinity of the crystalline polyolefin is preferably at least 30%, particularly preferably at least 50%. For example, typical crystallinity values for ordinary crystalline polyolefins are 50-60 for low density polyethylene.
%, 75-90% for high density polyethylene and 55-65% for polypropylene. Although the molecular weight is not particularly limited, polyethylene is about 200,000 to 80 in number average molecular weight.
About 100,000 to 400,000 for polypropylene is suitable.

As described above, polyethylene and polypropylene have high crystallinity and thus have a lower moisture permeability than butyl rubber. Among them, those having a lower melt viscosity than those of butyl rubber alone have the same composition as those of butyl rubber alone. Has a reduced melt viscosity and improves moldability. Therefore, various inorganic fillers can be compounded to realize a sealing agent having higher hardness, and these are particularly preferable from the viewpoint of economy.

In the sealing composition of the present invention, the ratio of the crystalline polyolefin to the total amount of the butyl rubber and the crystalline polyolefin is 2 to 50% by weight, preferably 5 to 40% by weight. If the proportion of the crystalline polyolefin is less than 2% by weight, it is difficult to increase the hardness of the butyl rubber, and if it exceeds 50% by weight, the properties of the crystalline polyolefin are mainly used and the properties of the butyl rubber are hardly exhibited.

When an inorganic filler is compounded, the ratio of the crystalline polyolefin to the total amount of the butyl rubber and the crystalline polyolefin can be small. For example, when about 50 parts by weight or more of the inorganic filler is blended with respect to 100 parts by weight of the total of the butyl rubber and the crystalline polyolefin, the ratio of the crystalline polyolefin to the total amount of the butyl rubber and the crystalline polyolefin is The desired effect is sufficiently exhibited at 2 to 20% by weight.

[0021] Substantially effective amounts of inorganic fillers can be incorporated into the sealant composition of the present invention comprising a butyl rubber and a crystalline polyolefin. The substantially effective amount refers to 1 part by weight or more based on 100 parts by weight of the total of the butyl rubber and the crystalline polyolefin. If an excessively large amount of the inorganic filler is added, the melt viscosity of the composition increases, and the tensile strength and the tear strength decrease. Therefore, the upper limit of the amount is 200 parts by weight, preferably 150 parts by weight.
The preferred lower limit of the amount of the inorganic filler compounded is 10
Parts by weight.

As the inorganic filler, calcium carbonate,
Those usually used as inorganic fillers, such as talc, mica and carbon black, can be used alone or in combination of two or more.

It is extremely effective that the butyl rubber and the crystalline polyolefin contained therein are mixed at a high temperature at least before the sealant composition of the present invention is used for final use. The high temperature in this mixing means a temperature higher than the crystalline melting point of the crystalline polyolefin. The mixing temperature must be lower than the decomposition point of butyl rubber, and is about 30 which is the decomposition point of normal butyl rubber.
0 ° C. or lower is preferred. 200 ° C especially in terms of productivity
The following is preferred. Therefore, the crystalline melting point of the crystalline polyolefin is also preferably 200 ° C. or less.

It is more preferable that the sealing agent has as small a change in hardness as possible in the temperature range of use. In order to satisfy these requirements, it is preferable that the crystalline polyolefin has a crystalline melting point higher than the normal upper limit temperature of use. The normal upper temperature limit for the use of the sealant is about 80 ° C.

In the present invention, since the crystalline polyolefin is constrained by the cohesive force of the crystalline phase, the rapid decrease in hardness and the flow state observed in the amorphous resin even in the temperature range exceeding the glass transition temperature are caused by the crystalline melting point. It does not happen below.
Conversely, a remarkable decrease in melt viscosity is seen around the crystal melting point,
The effect of improving the kneadability with the butyl rubber can be expected.

The sealant composition of the present invention may contain additives which can be generally added to the sealant. Such additives include, for example, desiccants, lubricants, pigments,
Antistatic agents, tackifiers, plasticizers, antioxidants, heat stabilizers, antioxidants, hydrolyzable silyl group-containing compounds such as silane coupling agents, foaming agents, fillers other than the inorganic filler, and the like. is there. Especially zeolite, silica gel,
It is preferable to add a desiccant such as alumina, a tackifier, a plasticizer, a silane coupling agent, and various stabilizers.

Among the additives, a desiccant such as zeolite is preferably incorporated in the sealing composition in an amount of 5 to 30% by weight. It is also preferable to add the relatively low-molecular-weight polyisobutylene described above as an additive that imparts a tackifying effect and a plasticizing effect to 200 parts by weight or less, particularly 5 to 150 parts by weight, based on 100 parts by weight of the butyl rubber. .

The sealant composition of the present invention can be produced by mixing at least the butyl rubber and the crystalline polyolefin at a temperature not lower than the crystalline melting point of the crystalline polyolefin and not higher than the decomposition point of the butyl rubber. preferable.
The mixing temperature is from 100 to 280 ° C, especially from 120 to 250
C. is preferred. Other formulations and additives may be mixed simultaneously, before or after the mixing. The composition of the present invention is a substantially thermoplastic composition and can be mixed with a conventional mixer such as a melt-mixing extruder or a kneader.

As described above, since the composition of the present invention is a substantially thermoplastic composition, molding can be carried out continuously with the mixing operation. Alternatively, the composition may be manufactured into a molding material such as a pellet, and then molded. As a molding method, a melt molding method such as an extrusion molding method or an injection molding method can be used. Further, the molded article can be manufactured by arranging the molded article at the end of the laminated glass material in which two or more glass plates are arranged to face each other, continuously with the molding operation. In this case, by using a high temperature composition coming out of the molding machine,
High adhesion to glass plate is obtained. In addition, the composition can be applied to a double-glazing material while suppressing a decrease in the temperature of the composition using an apparatus such as an applicator. This device is preferably a device that can be heated.

The physical properties of the sealant composition of the present invention used for final sealing use include JIS K7
149 is 4.0 × 10 ⁻⁷ [cm ³
Cm / (cm ² · sec · cmHg)] or less, especially 7.0 × 10 ^-8 [cm ³ · cm / (cm ² · sec · c)
mHg)]. Further, the JIS A hardness (HsA) at 25 ° C. is preferably 5 or more, particularly preferably 20 or more from the viewpoint of the shape maintenance of the double-glazed glass. Also, if the material is too hard, the stress applied to the sealing portion of the double-glazed glass or the glass plate may increase,
The upper limit of the hardness is preferably about 90.

The sealant composition of the present invention is particularly excellent for sealing the edge of a double glazing.
As this double-layer glass, it is preferable to use a double-layer glass having a structure in which the gap between the glass plates is maintained by the hardness of the sealing material without using a hard spacer such as a metal as described above. Since the sealing agent composition of the present invention can be used as a sealing material having an appropriate hardness by changing the compounding amount of the crystalline polyolefin and the inorganic filler, as a sealing agent composition for a double glazing having a structure not using this spacer. Suitable. The JIS A hardness (HsA) at 25 ° C. of the sealing agent composition of the present invention used for this purpose is particularly preferably from 40 to 90.

FIG. 1 is a cross-sectional view showing an example of a double-glazing unit having the above-mentioned structure. Double-glazing unit 1 is composed of two glass plates 1a and 1b, each of which is made of a sealing material comprising the sealing composition of the present invention. It is held at a predetermined interval only by the material 2. In addition, the meaning of the above “only by the sealing material 2” means
In addition, it indicates that a secondary sealing material, a metal spacer, or the like is not required, and does not exclude a primer treatment or the like applied as necessary.

The above-mentioned double-glazed glass is coated with an adhesive dissolved in a solvent on the glass surface where the spacer comes into contact, if necessary, and air-dried. Then, as shown in FIG.
1b at predetermined intervals (for example, 6 mm, 12 mm)
Next, using an extruder, the sealing agent composition of the present invention is melted at a temperature of, for example, 150 to 200 ° C.,
It is formed by interposing between two glass plates and cooling while extruding from a die having an appropriate tip shape. The method of forming the multilayer glass is an example, and the manufacturing method itself of the multilayer glass is not limited to the above method.For example, a sealing material having a desired shape is formed in advance from the sealing agent composition, and It may be formed by thermocompression bonding using two glass plates.

The glass plate used for the construction of the double glazing is
Generally, building materials, glass plates such as windows and doors widely used in vehicles, tempered glass, laminated glass, glass with metal mesh, heat absorbing glass, and even heat reflecting glass,
Such as a low-reflectance glass, a glass plate having an inner surface coated with a thin metal or other inorganic substance, an acrylic resin plate called organic glass, a polycarbonate plate, and the like are not particularly limited.

The double glazing may be composed of two glass plates, or may be composed of three or more glass plates.

The sealant composition of the present invention is not limited to the double glass sealant having the structure shown in FIG. For example, in a double-layered glass having a structure in which an end portion is sealed by combining a spacer made of a material harder than the sealing material (for example, made of metal or hard synthetic resin) and a sealing material, the sealing agent composition of the present invention is used as the material of the sealing material. Can be used. Further, the sealing agent composition of the present invention can be used as a sealing agent for building materials other than double-glazing.

[0037]

EXAMPLES The present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. Example 1 below
6 to 12 and Examples 12 are Examples, and Examples 7 to 11 are Comparative Examples.

Example 1 A butyl rubber having a Mooney viscosity of 47 ML (1 + 8) 100 ° C. was used as the butyl rubber, and a melt index of 2 was used as the crystalline polyolefin.
A high-density polyethylene (HDPE) having 0, a crystal melting point of 130 ° C., and a crystallinity of about 80% was used.

The butyl rubber and HDPE were melted and mixed at 160 ° C. and 20 rpm for 30 minutes using a Labo Plastmill. The hardness (HsA) was measured according to JIS K6301. The melt viscosity was measured by a capillograph at 160 ° C. and showed a value of a shear rate of 91 sec ⁻¹ . The water vapor transmission coefficient was determined from the speed of water vapor passing through the thin film by applying a water vapor pressure of about 20 mmHg to one side of the thin film at 60 ° C. and evacuating the other side. 16
Regarding the tackiness at 0 ° C. (high-temperature tack), ○ indicates that the necessary and sufficient tack was developed, x indicates that the tack was insufficient, and Δ indicates the middle.

Using the above materials and methods, butyl rubber 70
The composition consisting of 30% by weight of HDPE and 30% by weight of HDPE was evaluated. Table 1 shows the results. In Tables 1, 2 and 3, the numerical values of the composition of the materials represent% by weight, the melt viscosity is in units of 10 ⁴ poise, and the water vapor transmission coefficient is 10 ^−9.
The unit is cm ³ · cm / (cm ² · sec · cmHg).

Example 2 Using the same materials and method as in Example 1, a composition comprising 80% by weight of butyl rubber and 20% by weight of HDPE was evaluated in the same manner as in Example 1. Table 1 shows the results.

Example 3 Same butyl rubber and HD as in Example 1
Using PE and talc and HAF as inorganic fillers
A test was performed in the same manner as in Example 1 using a carbon black mold. 47.5% by weight of butyl rubber, 2.5% by weight of HDPE, 30% by weight of talc, 20% by weight of carbon black
Table 2 shows the results of the evaluation of the composition consisting of

Example 4 Using the same materials as in Example 3, 45% by weight of butyl rubber, 5% by weight of HDPE, 30% by weight of talc,
For a composition comprising 20% by weight of carbon black,
Table 2 shows the results of the evaluation performed in the same manner as in Example 3.

Example 5 A partially cross-linked butyl rubber having a Mooney viscosity of 45 ML (1 + 3) 121 ° C. was used as the butyl rubber, and the same HD as in Example 1 was used as the crystalline polyolefin.
Using PE, 80% by weight of partially crosslinked butyl rubber and HDPE
Table 3 shows the results of the evaluation of the composition consisting of 20% by weight in the same manner as in Example 1.

Example 6 Using the same partially crosslinked butyl rubber and HDPE as in Example 5, and polyisobutylene having a viscosity average molecular weight of 12,000 (hereinafter referred to as PIB-A), 67.5% by weight of partially crosslinked butyl rubber and 22.5% by weight of HDPE And a composition consisting of 10% by weight of PIB-A,
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.

Example 7 The same HDPE as used in Example 1
Table 1 shows the results of the evaluation alone as in Example 1.
The hardness was measured by HsD only in this example.

Example 8 Using the same materials and method as in Example 1, the results of evaluating a composition comprising 40% by weight of butyl rubber and 60% by weight of HDPE are shown in Table 1.

Example 9 The same butyl rubber used in Example 1 was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 10 Table 2 shows the results of the same evaluation as in Example 3 for a composition comprising 50% by weight of butyl rubber, 30% by weight of talc, and 20% by weight of carbon black using the same materials as in Example 3.

[Example 11] Table 2 shows the results of evaluating a composition comprising the same materials as in Example 3 and comprising 45% by weight of butyl rubber, 35% by weight of talc and 20% by weight of carbon black in the same manner as in Example 3.

Example 12 As a butyl rubber, polyisobutylene having a viscosity average molecular weight of 72,000 (hereinafter referred to as PIB-B)
Table 4 shows the results of the same evaluation as in Example 1 for a composition comprising 67.5% by weight, 10% by weight of PIB-A, and 22.5% by weight of HDPE as in Example 1.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

[Table 4]

[0056]

According to the present invention, the addition of polyethylene as shown in Table 1 increases the hardness without impairing the water vapor permeability and tack which are the characteristics of butyl rubber, and the addition of inorganic filler as shown in Table 2. In addition, high hardness could be realized only by adding a small amount of polyethylene. Further, as shown in Table 3, partially cross-linked butyl rubber can be used in place of butyl rubber, and polyisobutylene can be blended.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of the configuration of a double-glazing unit.

FIG. 2 is a cross-sectional view showing a configuration of a multi-layer glass before multi-layering.

FIG. 3 is a cross-sectional view illustrating an example of a configuration of a double-glazing unit.

FIG. 4 is a cross-sectional view showing an example of the configuration of a double-glazing unit.

[Description of Signs] 1a, 1b: glass plate, 1: double-glazed glass, 2: spacer.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yoshitaka Matsuyama 1150 Hazawa-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Asahi Glass Co., Ltd. Central Research Laboratory

Claims (4)

[Claims] A butyl rubber and a crystalline polyolefin, wherein the ratio of the butyl rubber to the total amount of both is 50 to 50.
A sealant composition comprising 98% by weight and a crystalline polyolefin ratio of 2 to 50% by weight. 2. A rubber composition comprising a butyl rubber, a crystalline polyolefin, and an inorganic filler, wherein the proportion of the butyl rubber to the total amount of the butyl rubber and the crystalline polyolefin is 50 to 98% by weight, and the proportion of the crystalline polyolefin is 2 to 50%. % Of butyl rubber and crystalline polyolefin.
A sealant composition wherein the ratio of the inorganic filler to 0 part by weight is 200 parts by weight or less. 3. The sealant composition according to claim 1, wherein the crystalline polyolefin comprises at least one polymer selected from polyethylene, polypropylene and modified products thereof. 4. An end seal for a double glazing according to claim 1.
Or the sealing agent composition of 3.